Recently developed arthroscopic, endoscopic, and laparoscopic surgical techniques have reduced the pain and discomfort normally experienced by patients undergoing traditional “open” surgery and decreases the recovery time and scarring common to such traditional surgery. These techniques are commonly performed in confined spaces, wherein one or more tubes may be inserted in the patient, and surgical instruments and materials are moved in to the surgery site through the tube or tubes. Accordingly, these surgical techniques require smaller incisions in a patient than traditional surgery in which an incision is made in a patient to open the site to be operated on to relatively unrestricted access.
Due to these smaller incisions, the suturing of tissue under the constraints of arthroscopic, endoscopic, or laparoscopic surgery, or any other form of non-open surgery, is difficult with the tools and instruments presently available. While many instruments have been proposed to solve this problem in the past, such instruments have been found to possess a number of drawbacks.
The presently available instruments or suture passers generally fall into two main categories. The first type of device is designed to propel a relatively rigid, usually monofilament, suture with mechanical force through a cannula or hollow needle through the tissue. These devices cannot pass more flexible, braided sutures through the tissue.
The second type of presently available device uses a solid needle or wire with a closed or open eyelet to carry the suture through tissue. However, a device with a closed eyelet provides for difficulty in removing the suture from the eyelet. Devices with an open eyelet may include a notch from which the suture can be removed without having to move a length of suture through a closed eyelet to correct this problem. However, the notch comprises an exposed surface which can catch on tissue, making passage through the tissue difficult. These devices also require other instruments to grasp and pull the suture free from the needle or wire.
A number of prior patents describe such presently known instruments. For example, U.S. Pat. Nos. 4,890,615 to Caspari et al.; 919,138 to Drake et al.; U.S. Pat. No. 3,840,017 to Violante; U.S. Pat. No. 4,224,947 to Fukuda; and U.S. Pat. No. 4,643,178 to Nastari et al. disclose suturing instruments wherein sutures are passed through hollow needles after the needles penetrate through tissue to be sutured. However, the use of these instruments has the disadvantage that the suture material must be grasped by an instrument not useful in arthroscopic surgery.
Similarly, U.S. Pat. No. 4,493,323 to Albright et al. and U.S. Pat. Nos. 4,602,635 and 4,621,640 to Mulhollan et al. disclose instruments for internal suturing in confined space, but require multiple instrument manipulation and movement of needles carrying sutures entirely through the tissue to be sutured. The Albright et al. patent in particular discloses a pair of needles that are forced outwardly through the end of a tube by a plunger to penetrate and extend through the tissue to be sutured. The needles are grasped and pulled by a surgeon to position a suture thread loop attached to the needles. Likewise, the '635 patent discloses an instrument for tying knots in sutures in a manipulation area external to the body after sutures are passed through the tissue. The knots are then forced into place adjacent to the tissue by another instrument. The '640 patent similarly discloses a curved needle carried by a pivoting head movable to set the needle in the tissue to be sutured. The needle is then released, the instrument is withdrawn, and another instrument is inserted to pull the needle through.
U.S. Pat. Nos. 1,815,725 to Pilling et al.; U.S. Pat. No. 3,470,875 to Johnson; U.S. Pat. No. 3,842,840 to Schweizer; U.S. Pat. No. 3,946,740 to Bassett; and U.S. Pat. No. 4,164,225 to Johnson et al. disclose suturing instruments having pivoted, scissor-like arms with a needle at the end of an arm forced through tissue to be sutured. The end of the arm is next forced into the end of another arm, where the suture is grasped or clamped. The instruments are of a structural design that is not practical in arthroscopic surgery.
U.S. Pat. No. 4,312,337 to Donohue discloses an instrument for drilling and wiring bones. Scissor-like arms carry cannula sections through which a wire is passed, the wire being cut and tied after the cannula sections are withdrawn. The structure is such that it does not permit the instrument to be used in arthroscopic surgery.
In addition to their inconvenience in use in arthroscopic surgery, these prior art devices present other drawbacks as well. For example, the '615 patent to Caspari et al. noted above discloses pushing a suture through a hollow needle. A suture feed mechanism adjacent to a proximal end of the needle (the end of the needle closer to a surgeon's hand) comprises rollers which grasp the suture and push it toward a distal end of the needle. Pushing the suture through the hollow needle requires a suture stiff enough to be pushed, such as, for example, a monofilament suture. However, soft, braided sutures are easier for a surgeon to manipulate and tie and are thus generally preferable. Soft braided sutures are not typically suited to being pushed from a proximal end to a distal end of a hollow needle.
The presently known suturing instruments and methods, then, are of limited effectiveness for use in closely confined spaces such as sites of arthroscopic surgery. Accordingly, there remains a need in the art for suturing instruments and methods designed for and effective in providing sutures in the closely confined spaces provided by, e.g. arthroscopic surgery. The present subject matter addresses this need.